Date: Tue, 7 Dec 2021 23:38:41 GMT From: John Baldwin <jhb@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 8099a354469a - main - libkvm: Fix kvm_getloadavg() on modern kernel vmcores Message-ID: <202112072338.1B7Ncfk7075959@gitrepo.freebsd.org>
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The branch main has been updated by jhb: URL: https://cgit.FreeBSD.org/src/commit/?id=8099a354469a012512d9850302edaa0e27c75fd7 commit 8099a354469a012512d9850302edaa0e27c75fd7 Author: Michał Górny <mgorny@gentoo.org> AuthorDate: 2021-11-07 21:11:52 +0000 Commit: John Baldwin <jhb@FreeBSD.org> CommitDate: 2021-12-07 23:36:34 +0000 libkvm: Fix kvm_getloadavg() on modern kernel vmcores Fix kvm_getloadavg() to work correctly on vmcores for modern kernel versions. The kernels no longer include the `_fscale` symbol causing the kvm_nlist() invocation to fail. The code seemed to already assume that `_fscale` could be missing but the early kvm_nlist() result check has caused the function to fail if any symbol were missing. Modify it to only treat `_averunnable` as obligatory, and handle missing `_fscale` gracefully. Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D32884 --- lib/libkvm/kvm_getloadavg.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/lib/libkvm/kvm_getloadavg.c b/lib/libkvm/kvm_getloadavg.c index 0f2a5f69bcf0..f94b1d844663 100644 --- a/lib/libkvm/kvm_getloadavg.c +++ b/lib/libkvm/kvm_getloadavg.c @@ -62,7 +62,6 @@ int kvm_getloadavg(kvm_t *kd, double loadavg[], int nelem) { struct loadavg loadinfo; - struct nlist *p; int fscale, i; if (ISALIVE(kd)) @@ -74,10 +73,9 @@ kvm_getloadavg(kvm_t *kd, double loadavg[], int nelem) return (-1); } - if (kvm_nlist(kd, nl) != 0) { - for (p = nl; p->n_type != 0; ++p); + if (kvm_nlist(kd, nl) != 0 && nl[X_AVERUNNABLE].n_type == 0) { _kvm_err(kd, kd->program, - "%s: no such symbol", p->n_name); + "%s: no such symbol", nl[X_AVERUNNABLE].n_name); return (-1); } @@ -92,7 +90,8 @@ kvm_getloadavg(kvm_t *kd, double loadavg[], int nelem) * Old kernels have fscale separately; if not found assume * running new format. */ - if (!KREAD(kd, nl[X_FSCALE].n_value, &fscale)) + if (nl[X_FSCALE].n_type != 0 && + !KREAD(kd, nl[X_FSCALE].n_value, &fscale)) loadinfo.fscale = fscale; nelem = MIN(nelem, (int)(sizeof(loadinfo.ldavg) / sizeof(fixpt_t)));
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